Means for tapering ends of tubular objects



May 9, 1944. i Q. E. BASHORE MEANS FOR TAPERING ENDS OF TUBULAR OBJECTS Filed April 23, 1943 5e 46 2s l7\ 6 2;) 33

2a 27 30 l2 la 47 525 57 FOR 77 /5 FIRM 47-7-0 P? NE v5 Pas ed May 9, 1944 UNITED ,sTAT-Es PATENT. 1 3 f Q I trams son rurgggms 0F ruauuin Quinter a. Bashore, Oovina, can.

Application April 23, '1943, Serial No. 484,222 is Claims. (c1. sz-ni My invention relates to machining devices and is directed particularly to improvements in portable devices for cutting the ends of tubular ob- ,jects to tapered or conical configuration.

Since the invention has been initially embodied in a portable tool for use in the field to taper ends of conduit, such embodiment is selected for the purpose of the present disclosure. Those skilled in the art will find in my description adequate guidance for applying the invention to other purposes in other fields.

Lengths of pipe and conduit for various purposes are commonly joined together in the course of installation by telescoping the end of one length into theadiacent end of the'next length,

usually with suitable cement or sealing material applied to the telescoping surfaces. The invention is being used initially for the installation of underground electrical conduit in air fields, which conduit is made of a fibrous composition including as ingredients asbestos fiber and suitable cement.

Each factory length of the composition conduit is supplied with an external taper at each end and with a complementary tapered coupling for joining purposes. For a long run, it is merely necessary to fit together the factory lengths until the ends of the run is reached. The last length of the run, however, must be cut and the cut end of the conduit must be tapered externally for the purpose of making a proper joint. Usually, the cut end of the conduit is joined to a suitable outlet box or rigid conduit. To make a juncture with an outlet box, the externally tapered end of the conduit-is fitted into the internally tapered end of a special sleeve, and the sleeve in turn is connected with the outlet box by a union.

Since the wiring of an air field involves numerous short runs, it becomes necessary to finish many out ends of conduit to the required external taper. In practice, a string of factory lengths of the composition conduit is laid along a required course and then the string is cut at numerous points for insertion of the required outlet boxes. Heretofore the practice has been either to transport the newly cut lengths of conduit to a remote shop for beveling or .to providea shop or heavy machine on wheels for use in the field.

It is one object of my invention to providefor this purpose a simple portable tool so light thatit may be applied manually to the cut end of a conduit in a trench in the ground without the necessity of removing the cut length of con-;

duit from the previously laid string. Another object of the invention is to provide such a tool in the form of a rotary device that may be attached to and actuated by a simple portable 5 power means for employment in the well known manner of a manually portable rotary drill.

Heretofore the heavy machines for tapering the cut ends of such composition conduit have been grinding devices requiring five to ten min-v utes to process a conduit end. One object of my invention is to provide a rotary cutting device to accomplish the same task in less than a minute. Another object is to make such a tool adjustable in a simple manner for beveling conduit of diilerent diameters. A still further object is tOdDlOVldG a tool that will not only bevel a conduit end but also will automatically correct any departure of the conduit from cylindrical configuration. Thus the end of a fibrous conduit that flattens slightly out of roundirom lying in the sun over an extended period of time is automatically reshaped by my device prior to the cutting operation. a

Other objects and advantages of my invention will be apparent in the detailed description to follow, taken with the accompanying drawing.

In the drawing, which is to be regarded merely as illustrative,

Fig. 1 is a side elevation of the preferred embodiment of my invention;

Fig. 2 is a longitudinal section taken as indicated by the line 2-2 of Fig. l; and

, Fig. 3 is a transverse section taken as indifor cutting this bevel include: a mandrel generally designated l2 adapted to be inserted in the end of the conduit in a fixed manner: a rotary means generally designated l3 adapted to telescope rotatably over a protruding portion of the mandrel; and at least one tool-holder means carried by the rotary means 13 and controlled by the mandrel I! with respect to the depth to, which the material oi the conduit Ill is cut by the device. In the present form of the invention, there are two tool-holdermeans designated l5 and I6, respectively, positioned diametrically opposite each other.

The mandrel I! may be adapted to expand radlally into fixed engagement with the surround ll ing material of -the conduit l0 and'preierably is Ii. The principal parts of the illustrated device tube that is extensively slit longitu vicinity of the pin 8| as indicated at adapted to expand equally in various radial directions so that the mandrel in engaging the,con-.-

conduit II, the flexible longitudinal sections it may have'suitably'broken surfaces. One manner of providing'such surfaces for the longitudinal sections II is to employ a welding procedure to build one up or more longitudinal ribs on each ofthe longitudinal sections. The drawing shows it and II, the rotary means It is provided with two radially extending brackets II on which the tool-holder means are mounted by suitable pivot bolts 4i carrying nuts 4!. Preferably, each of the brackets II has a plurality of sets of holes 48 for the corresponding pivot bolt 4| so that the toolholder means II and It may be shifted in posi- .tion outwardly and inwardly iorbeveling conduit of various diameters. The drawing shows each A eirective frictional engagement-of the expansible' cylinder n with the surrounding material of the of the tool-holder means II and II to be in the form of a lever having what may be termed a vforward cutting arm ll and a'rearward control aim it. Each cutting arm 48 is suitably-aper- ,tured to receives cutting tool and is provided with a suitable setscrew ii for releasabiy securingthecuttingtool. I

As indicated in the drawing, the tool-holder means It may carry at arelatively advanced positions cutting tool I to make a preliminary one such rib 22 of welding material on each of I the longitudinal sections 2 I The opposite ends ofthe' expansible cylinder li'are internally tapered to conform to a forward circular wedge 23 and a rmward circular wedge 24 on which the expansible cylinder is mounted.

It is merely n' to lessen. the distance bea tween .the two v circular wedges to cause the cylinder to expand radially into engagement with the conduit. The rearward circular wedge 23 is rough cut and the tool-holder means it may carry a following cutting tool ll of lesser inclination for a finishing cut. Preferably. at least one of the two cutting tools is turned on its axis'to an angle relative tom plane perpendicular to the axis of the mandrel to cause the cutting action ;to lead or feed the rotary means is by what may be termed a screw-thread effect. Thus. the

drawing shows both of the cutting tools II and 5! shown backed against a collar or radial flange 25 on the axial member it in a freely rotatable mannerand the forward circular wedge 23 is illustrated as internally threaded for engagement by a screw thread 21 on the forward end of the axial slightly twisted about their axes to cause such feeding action when the rotary means is is rotated in the direction indicated by the arrow in 18. 2.

It is contemplated that the two tool-holder means it and i6 will cooperate with the tapered portion 82 of the mandrel to regulate the depth of cut of the two cutting means iii and BI as the rotary means isadvanced relative to the, man- .membenl Means, such as a cotter pin 28, may be employed to limit the forward axial movement of the forward circular wedge 23 relativeto the axial member ll. Preferably, suitable means isprovided to prevent relative rotation between the forward circular wedge 23 and the expansible' cylinder II. for example, a pin 30 .carried by the circular wedge and extending into one of the iongitudinal slits- 20' of the cylinder. Fig. 1 shows one of the longitudinal slits II cut away in the Ii to permit theuseofarelativelythick pin.'

Rearwardly of theexpansible cylinder I! the drel. For this purpose I may thread a screw 52 transversely through each of the control arms 48 toward the axis of rotation; the rotary means it being provided with suitable openings 58 through which the screws extend into contact with the tapered portion 32 oil the mandrel. To

maintain the screws 52 in adjustment, lock-nuts 65 may be provided.

While the two tool-holder means It and it may be so designed that centrifugal action will tend to throw the cutting arms 45 outward and axial member is has a conically tapered portion 32 for-governing the depth to which the materialof the conduit "is cut and, additionally, has at least one cylindrical bearing portion for axial guidance of the rotary means 13. In Fig. 2 the axial member is is shown with a bearing portion 3 it forward of. the tapered portion 32 and a second bearing portion 34 rearward of the tapered portion 32.

The rotary means It may be of any suitable construction providing for rotation relative to the mandrel I! with sumclent force to cut the material of the conduit iii. In the vpreferred form of my device, the rotary means i 3 is shaped with a stem or shank 35 for engagement by the chuck of a suitable power means such as a manually portable power means commonly employed for drilling holes in metal; Therotary means it has an axial bore 31. dimensioned for cooperation with the two bearing portions 83 and 84 of the axial member it for axial guidance of the rotary means in the process of cutting away the material oi the conduit i0.

For the support of the two tool-holder means'is thereby urge the screws 52 against the periphery of the mandrel portion 32, I prefer to rely upon suitable yielding means to the same end. Thus, the drawing shows each control arm 46 having a bore 66 to clear a radial bolt it anad a counterbore 57 to seat a helical spring in compression between the control arm and the head of the bolt. The springs til .continuously urge the adjustment screws 52 into contact with the tapered mandrel portion 32. v

The manner in which the deviceoperates may be readily understood from the foregoing descrip- 7 tion. Preliminary to insertion of the mandrel it into the end of the conduit It the expansible cylinder Il may be expanded to a degree providing for a sliding fit in the conduit. After insertion of the mandrel the axial member I8 is rotated to draw the circular wedge 23 toward the" .circular wedge 24, thereby to expand the cylinder l1 into gripping engagement with the surrounding material of the conduit. The operator then telescopes the rotary means it over the axial member 18, thereby positioning the two cutting tools iii and 5! at the edge or rim oi the conduit. Dotted lines in Fig. 2 show the approximate positions at this time of the two cutting tools and the two setscrews 52. The opermeans it and advances the rotary means to carry out the cutting operation. As the'rotary means l3 advances. the two screws 52 progressively move radially inward as they traverse the tapered mandrel portion 32 and correspondingly cause the two cutting'tools it and ii to progressively move radially outward as thecutting tools advance on 1 I object. the combination oi; aman the conduit i0.

Preparatory to cutting a bevel on a'pipe of larger'diameter, the two tool-holder means I! and it may beshiited to outer holes 43 on'thebracket 4D. Diiiferent mandrels for conduits of v diflerent diameter may be kept available or; in an alternative practice, expansible cylinders ll of different diameters with corresponding sets of circular wedges 23; and 24 may be kept, aaailable for interchangeable ,mounting on the axi'aigmembet '8. is: The preferred practice of my invention; de-

scribed in detail herein will suggest to those skilled'in the'art various changes and substitutions'under my basic concept. and I- reserve the claims.

' said mandrel for axial guidance thereby; cutting" means carried by said rotary means; and means carried by said ..rotary means and controlled by said mandrel as said rotary means 'isadvanced relative to the tubular obiect.

'2. In a device of the character described tor member relative to the cylinden s. In a device of the character described for" cutting an exterior bevel on the end at a tubular.

tial insertionin the end oi'said tubular object in 'ailxed manner,- said mandrelhaving a tapered portion positioned to lie outsidethe :tubular' obiect;' rotary means to rotatably engage said mandrel Dior axial. guidance thereby; cutting means carried by said rotary means; and means carried by said rotary means and controlled by said tapered mandrel portion to vary the radial distance of said cutting means irom the axis oi said mandrel as said-rotary means is advanced a relative to the tubular object.

6. In a device of the character described for cutting an exterior bevel on the end of a. tuburight to all such departures from my disclosure that properly lie within the scope of my appended 'iectinto fixed engagement with the tubular ob rtion in the end of said tubular obiect, said mandrel having both a bearing portion and a tapered portion positioned to lie outside 'the tubular object; rotary means to rotatably telescope over said bearing portion or the man- 'drel tor axial guidance thereby; cutting means carried by said rotary means; and means carried by said rotary means and controlled by said tapered mandrel portion to vary the radial distance of said cutting means from the axis of said mandrel as said rotary means is advanced relative to the tubular object.

' [said mandrel portion to increase the radial distance of said cutting means from the axis of' 7. In a device of the character described for cutting an exterior bevel on the end of a tubu- 'lar object, the combination of: a mandrel having cutting an exterior bevel on the end of a tubular object, the combination of: a mandrel for insertion in the end of the tubular object with a portion of the mandrel protruding therefrom,

said mandrel being expansible equally in various tubular object.

3. In a device of the izharacterfdescribed for cutting an exterior bevel on the-end of a tubular object,'the combination of: a radially expanslble cylinder for insertion in the end of said tubular object; an axial member carrying said cylinder,

said member having a portion positioned to pro- -trude from the end of the tubular object when said cylinder isinserted;means carried'by said axial member ,to expand the inserted cylinder into engagement with the tubular object; rotary means to rotatably engage said axial member for.

axial guidance thereby; cutting means carried by said rotary means; and means carried by said rotary means and controlled by'said axial member to increase the radial distance of said cutting means from the axis of said cylinder as said rotary means is advanced over the end of the tubular obiect.

radial directions for anchorage in said tubular v a radially expan'sible portion for insertion into and engagement with the end oi. said. tubular object, said mandrel having a tapered portion positioned to lie outside the tubular object; rotary means to rotatably telescope oversaid portion of the mandrel for axial guidance by the mandrel; cutting means carried by said rotary means; and means carried by said rotary means and controlled by said'tapered mandrel portion to vary the radial distance of said cutting means from the axis'oi said mandrel as said'rotary means is advanced relative to the tubular object.

. 8. In a device of the character described for cutting an exterior bevel on the end of a tubular object, the combination oi: a mandrel for partial insertion in the end of said tubular object,

- in a fixed manner, said mandrel having a tapered portion positioned to lie outside the tubular obiect; cutting means; rotaryi means to rotatably engage said mandrel; tool-holder means mounted on said rotary means to carry said cutting means, said tool-holder means being movable to vary the cutting depth of said cutting means; and means for contact with said tapered portion to vary the radial position of said tool-holder means as said'rotary means'is advanced.

9. In a device of the character described for cutting an exterior bevel on the end oi. a tubular object, the combination or: a mandrel for partlal insertion in the end of-said tubular object in a fixed manner, said mandrel having a tapered portion positioned to lie outside the tubular Y object; rotary means to rotatably engage said mandrel; cutting means; tool-holder means mounted on said rotary means, said tool-holder 4. In aidevice oi the character described, a combination as set forth in claim 3 in which; said cylinder is longitudinally slit for radial expension and in which-said means ior expanding I the cylinder is responsive to rotation of said axial ior partubular object.

meanscarrying said cutting means and being movably mounted on the rotary means to shirt said cutting .means radially relative to the axis of rotation; and yielding means to urge'said tool-holder meansinto contact with said tapered portionoi the mandrel, whereby the distance oi said cutting means irom the axis 01' rotation is progressively. changed as saidrotary means ad- I vances: axially relative to said mandrel. I

10. a device of the character described ior cutting an exteriorbevel on the end or a tubular obiect, .the. combination or: a mandrel for insertion in the end of the tubular object in a flxedmanner with a 'portion oi the mandrel protruding-therefrom; rotary means to rctatably engage said mandrel for axial guidance thereby;- cutting means carried by saidrotary means; and

means'carried'by said rotary means and controlled by said mandrel portion to increase the radial distance oi." said cutting means from the axis of saidimandrel as said rotary means is advanced relative to the'tubular object, said cut-' ting means being turned out or a plane perpendicular tothe axis of rotation or said rotary means in a direction to cause the cutting actionmeans toward said' to feed said rotary 11. In' a device of the character described .ror cutting an exterior bevel on the end or a tubular object, the combination diz a mandrel for parsaid cutting means mm the axis of rotation is progressively changed as said rotary means advances axially relative to said mandrel, said cutting means being turned out of a plane perpendicular to the axis of rotation in a direction to cause the cutting action to feed said rotary means axially relative to said tubular object. 1

13. In a device of the character described ior cutting an exterior bevel on the end bi a tubular obiect, the combination of: a mandrel having a radially expansible portion .ior insertion into and engagement with theend of said tubular object, said mandrel having both a tapered portion and a cylindrical portion positioned to lie outside the tubular object; rotary means to rotatably telescope over said mandrel, said rotary;means having a cylindrical portion to cooperate with said cylindrical portion of the mandrel foraxial guidance or the rotary means; cutting means; tool-holder means mounted on said rotary means,

. said tool-holder means carrying said cutting theaxis of rotation; and yieldingmeans to urge tial insertion in the end of said tubular object into fixed engagement with the tubular object,

' said mandrel having both a bearing portion and holder means into contact with said tapered por--- tlon oi the mandrel, whereby the radial distance of said cutting means from the axis 01 rotation is progressively changed as said rotary means ,advances axially relativeto said mandrel.

L 12. In a device 01 the character described for cutting an exterior bevel on the end of a tubular object, the combination of a mandrel for partal insertion in the end of said tubular object into fixed engagement with the, tubular object, said mandrel havingboth a bearing portion and a tapered portion positioned to lie outside the tubular object; rotary means to rotatably telescope over said mandrel, said rotary means hav.-.

ing abearing portion cooperative with said bearing portion of the mandrel for axial guidance of the rotary means; cutting means; tool-holder means mounted on said rotarymeans, said toolholder means carrying said cutting means and being movably mounted on the rotary means toshift said cutting means radially relative to the axis oirotation; and yielding means to urge said tool-holder means into contact with said tapered 1 portion or the mandrel, whereby the distance of.

- tary means.

means and being movably mounted on' the rotary means to shift said cutting means relative to said tool-holder means into contact with said tapered portion of the mandrel. whereby the distance or said cutting means from the axis of 1 rotation is progressively changed as said rotary means advances axially relative to said mandrel.

14. In a device of the character described, a combination as set forth in claim 9 in which said tool-holder means is pivotally mounted on said rotary means to swing toward and away from the axis oi rotation of the rotary means, and in which said yielding means is a spring means acting between said tool-holder means and said ro- 15. In a device of the character described ior "cutting an'exterior bevelon the end of a tubular object, the combination of: a radially expansible cylinder for insertion in the end of said tubular object; an axial member carrying said cylinder, said axial member having a tapered portion positionedto lie outside the tubular object when said expansible cylinder is inserted in the tubular object; means carried by said axial member to expandlthe inserted cylinder into engagement with the tubular object, thereby to flx said axial member relative to the tubular object; rotary means to rotatably engage'said axial member for axial guidance thereby; cutting means; tool-holder means mounted on said rotary-means, said tool-holder means carrying said cutting means and being movably mounted on the rotary means to shift said cutting means rel- L ative to the axis of rotation; and yielding means to. urge said tool-holder means into contact with said tapered portion oi said axial member,

' whereby the radial distance of said cutting means from the axis of said tubular object is progressively varied as said rotary means advances axially' relative to said =mandrel.

i6. In a device of the character described a combination asset forth in claim 8 .in which.

said rotary means is adjustable radially of said ,rotary means, whereby the, device may be adapted to tubular objects of various diameters.

QUIN'I'ER n BASHORE. 

